The Franklin Institute, bursting with Spider-Man, Hulk, and other images straight from the world of comics and blockbuster movies, has extended the run of its super-popular exhibit, “Marvel: Universe of Super Heroes,” to Sept. 11, and has extended its evening hours to 8 p.m. until the show closes.

The exhibition, an homage to the non-natural world of popular fantasy, looks as though it will attract 300,000 visitors over the course of its nearly five-month run, making it the second biggest summer draw ever for the Franklin Institute, albeit a long way from No. 1, 2007′s “Tutankhamun and the Golden Age of the Pharaohs.”

Tut pulled in about 1.3 million visitors over the course of its eight-month run, a number that surprised even institute officials at the time.

But 300,000 is hardly shabby visitation for “Marvel,” which features more than 300 original artifacts, including some of Marvel’s most iconic costumes, props, and original art.

An institute spokeswoman said retail sales of memorabilia and tchotchkes have already topped $1 million, second only to the gross for King Tut. (Figures for Tut were not immediately available.)

“The exhibit opened after a record-breaking ticket presale, the early buzz was remarkably positive, the overall response from visitors has been phenomenal, and the blockbuster film releases this anniversary year made the Philadelphia run even more significant.” said Larry Dubinski, president and chief executive of institute.

This summer marks Marvel’s 80th anniversary, which the institute will honor on Saturday, Aug. 31, exhibit by presenting visitors with a commemorative button displaying “Marvel 80th” artwork.